In previous experiments we have induced chronic atherosclerosis in rabbits, closely resembling atherosclerosis in man, by means of the synergy of immunological arterial injury and lipid-rich diets. We are continuing investigations designed to determine whether modest decreases in serum cholesterol resulting from changes in diet like those recommended for man will halt progression or lead to regression of similar chronic coronary and aortic atherosclerosis in rabbits. BIBLIOGRAPHIC REFERENCES: Jaffe EA, Minick CR, Adelman B, Becker CG and Nachman RL: Synthesis of basement membrane collagen by cultured human endothelial cells. J Exp Med, 1976, 144:209-225. Minick CR: Immunological arterial injury in atherogenesis. Ann NY Acad Sci, 1976, 275: 210-227.